Carbon and gum remover



Patented Aug. 30, 1938 2.128.685. cannon AND GUM nEMovnn Wallace 3. Yates, Martinez,

Shell Development Company,

Galif., assignor to San Francisco,

Oaliit, a corporation of Delaware No Drawing. Application November 23, 1936, Serial N0. 112,297

3 Claims.

bustion of the combustible charge. Carbon is also formed from the lubricating oil which has seeped up to or past the'piston rings and is oxi- 15 dized at the'high temperature in the cylinder in the presence of the oxygen of the fuel mixture. At the same time, gums are formed which act as a binder for the carbon particles, which serves to cement them tightly onto the cylinder head,

20 the top of the piston,-the rings, and other metal parts defining the combustion space.

Such carbon deposits have long presented 'a' serious problem in the operation and mainte-' nance of gasoline and Diesel engines, being par- 5 ticularly acute in the latter, where the carbon deposits frequently, in-a short time, cause sticking of the piston rings to the extentthat they fail to seal the combustion chamber irornthe crankcase. This leads both to loss ct power 30 and excessive oil consumption.

Various solvents, such as alcohol and benzol, have been used in attempts to dissolve such deposits. These solvents have been found to have a solvent action on part of the binder holding the carbon encrustation onto the metalparts, but have not been effective in removing a substantial portion of the deposit in a short period r of time.

One of the principal objects of this invention is to provide asuperior composition which is unusually effective in removing carbon deposits from internal combustion engines.

Another object oi. the invention is to provide such a composition for removing such carbon 45 which is cheap and has no deleterious efiects upon the usual metalparts with whichit comes into contact.

Another object is to provide a carbon removing composition that can. be easily applied either 50 to the assembled parts of the engine or to the parts after removal from the engine. o

Other objects and advantages of the invention will be apparent from the following description.

I have found that a combination of certain solvents and soap has a most remarkable eileot in removing carbon deposits. In particular, soap, alcohol, water, volatile aromatic hydrocarbon, and lubricating oil obtained from petroleum have proven to make a suitable combination.

By the application of this mixture to the encrustation, the penetrating and solvent action is such that carbon is quickly loosened and falls off, leaving the metal'surface clean.

My invention is most useful in loosening piston rings, which, owing to gum and carbon formation, become glued to the pistons upon which they are mounted. The methods by which my composition is most advantageously applied are described in a subsequent portion of this application. By way of example of a carbon remover made according to my invention, the following is given:

Percent by volume Edeleanu extract of boiling range 135 C.-

195 C 42. 25 Motor lubricating oil obtained from petroleum 30 Lard oil 10 28% NHs solution .75 O1eic acid 3.5 Water 2.5 Secondary butyl alcohol 11 Instead of using motor lubricating oil obtained from petroleum and lard oil, I may substitute said motor lubricating oil entirely, which will have the same effect, namely, to prevent the quick evaporation of the Edeleanu extract, and to serve as a lubricant when the engine is first started after removal of carbon.

Instead of using ammonia to forma soap with oleic acid, I may substitute sodium hydroxide, potassium hydroxide, or an organic base such as tri ethanola-mine. Instead of oleic acid, I may use stearic acid, palmitic acid, or other fatty acids. The soap assists in penetrating between the carbon particles, and between the carbon encrustation and the metallic, assisting the action of the solvent, and also in helping to loosen the carbon deposit from the metal in the form oiflakes. Instead of using secondary butyl alcohol, I may use other a1co'- hols, for example, normal but'yl, isobutyl, tertiary weight alcohols. The alcohol serves the purpose of keeping the soap and water in solution in the mixture, and also as a solvent for gums binding the carbon particles. In the case of oil soluble soaps, such as triethanolamine oleate, the alcohol in the coinsurface, thereby butyl, isopropyl, ethylene glycol mono butyl ether, or higher molecular position may be dispensed with. The water is desirable to enable the soap to perform its function more effectively. Edeleanu extract is a most valuable solvent for the hydrocarbon gums which are the chief constituent binding the carbon to the metal surface. Instead of using an Edeleanu extract of boiling range of from 135-195 C., I may use a volatile Edeleanu extract of lower or higher boiling range, or equally well, purely aromatic hydrocarbons such as benzene, toluene, xylene, or their higher boiling homologues. The advantage of using a relatively high boiling solvent as initially mentioned, e. g., 135-195 0., lies in its high flash point, which provides a safety factor when introducing the product into warm engines, as say, through spark plug openings. Edeleanu extract as used herein may be described as a petroleum hydrocarbon fraction obtained by subjecting a hydrocarbon fraction to the low temperature liquid sulphur dioxide treatment invented by Dr. Edeleanu. The extract is separated from the sulphur dioxide by allowing the sulphur dioxide to evaporate, yielding a product having an aromatic content of approximately 40-70% by volume.

The lubricating oil does not serve as a carbon remover, but rather tends to reduce the activity of the other constitutent s, and is used primarily in order to ensure that a film of lubricant is left on the parts after cleaning. Where this is not necessary, the lubricant can be omitted from the composition.

As a further example of my invention, I may use a carbon remover of the following composition:

.Percent by volume Edeleanu extract 41.5 Motor lubricating oil 40 Ammonium oleate 4 Sec. butyl alcohol 12 Water 2.5

The carbon remover may be applied to the. carbon deposits either'while the engine is assembled or after removal of pistons and other parts. In the former case, it is customary to apply the product to pistons and rings in place when the engines have been shut down. For this purpose one to two ounces of carbon remover are added per cylinder and allowed to remain until the en-- gine is next used, preferably standing over night. The preferred method of placing carbon remover in the engines is through the spark plug openings, or, in the case of Diesel engines, by removing the fuel injectors and pouring through the openings into the cylinders, although pouring directly through the exhaust valve ports can ordinarily be used with a reasonable degreeof success. Application of the carbon remover. in this manner has been found to soften and loosen carbon in the combustion chamber and on the piston rings which is largely blown out through the exhaust after starting the engine. For particularly large engines, the amount of carbon remover used per cylinder should be increased.

When used to prevent sticking of piston rings it is desirable, because of the small clearance between piston rings and their grooves and the depth of the grooves, which restricts contact between the carbon remover and the carbon deposits, to apply the carbon remover at regular intervals, depending upon the type of engine and the severity of operation. This serves to remove the encrustation before it becomes thick and dense and so prevents piston rings from sticking. Another method. for preventingpiston rings from sticking and loosening those that have become stuck, consists in adding carbon remover to the lubricating oil, using preferably about one part of the former to five of the latter. The engine should be run for about eight hours with this mixture in the crankcase, after which it should be drained and replaced with straight lubricating oil.

When cleaning the parts of the engine by hand, they may be placed in a container of the mixture and allowed to soak. The carbon deposit on softening may be wiped off. In cases where the pistons have been removed and the rings have become glued to the piston, the latter is placed in a container of the mixture and allowed to soak for a considerable time. When not-badly stuck,

the rings may readily be loosened in their grooves and removed from the piston. Where'the rings are so badly stuck that they are not loosened by the remover, however, the rings may first be removed in parts and the pistons then soaked in the carbon remover, thus softening the carbon and enabling its removal without injury to the pistons, which frequently occurs when the customary scraping tools are used directly on the hard carbon. The mixture may be reused as long as effective. It should be understood that various changes may be made in the constituents and proportions of the composition without departing from the scope of my invention which, generally stated, consists in the matter described and set forth in the appended claims.

I claim as my invention:

1. A composition of matter for the removal of carbon deposits from internal combustion engines comprising by volume approximately 42 parts liquid sulfur dioxide soluble portion of volatile petroleum hydrocarbon oil, 40 parts lubricating oil obtained from petroleum, 4 parts alkali,

metal soap of oleic acid, 12 parts liquid aliphatic alcohol and 2.5 parts water.

2. A composition of matter for the removal of carbon deposits from internal combustion engines comprising by volume approximately 42 parts liquid sulfur dioxide soluble portion of volatile petroleum hydrocarbon oil, 40 parts lubricating oil obtained from petroleum. 4 parts water soluble oleic acid soap, 12 parts liquid aliphatic alcohol and 2.5 parts water.

3. A composition of matter for the removal of carbon deposits from internal combustion .en-- gines comprising by volume approximately 42 parts liquid sulfur dioxide soluble portion of volatile petroleum hydrocarbon, 30 parts lubri-- eating oil obtained from petroleum, 10 parts lard oil, 4 parts water soluble oleic acid soap, 11 parts liquid aliphatic alcohol and 2.5 parts water.

WALLACE J. YATES. 

